It is known to use a plasma cutter to cut a material, such as, for example only, steel, sheet metal, aluminum, and the like. In general, plasma cutting is performed by projecting an inert gas or compressed air from a source through a plasma torch nozzle towards the surface of the material to be cut, and simultaneously driving an electrical current through the gas or air by applying a voltage between the cutter and the material to form a plasma within the projected gas or air. The generated plasma is hot enough that it can be used to cut a variety of different materials. Other sheet metal cutting methods include laser cutting, waterjet cutting and oxy-fuel cutting.
In general plasma cutting systems typically include a power supply, ground, and a torch and can be used manually to cut the material. However, Computer Numerical Controlled (CNC) plasma cutting systems employ additional hardware and software to facilitate automated and often more precise material cutting. An exemplary system uses control hardware and software along with rails, carriages, gantries and stepper or servo motors to control the motion along the movement axis for precision cutting. Exemplary embodiments of a plasma cutter and material are shown in FIGS. 1 and 2.
When a plasma cutter first turns on and begins cutting a material, it takes time for the plasma jet to pierce through the material (i.e., to achieve an adequate Z-plane depth of the cut). During this time, the plasma needs to stay stationary with respect to the material before it can be moved to continue the cutting of the material (i.e., in the XY plane). The time for this initial piercing can vary according to the properties and thickness of the material to be cut, along with the characteristics of the plasma cutting device, such as, the power of the plasma system, nozzle geometry, and other factors.
One known method for determining the amount of time for this initial piercing to occur is to estimate the amount of time based on past experimental data, which can be then used to create a look-up table based on the characteristics of the material and of the plasma cutting system. However, such look-up tables can be imprecise resulting in insufficient cutting. If the time given in the table is too long, there will be a larger-than-desired dilated hole at the beginning of the cut. If the time in the table is too short, the plasma may not cut all the way through the material at the beginning of a cut. Also, the look-up table may not take into account variable thicknesses in the material being cut.
Another disadvantage of current sheet metal cutting systems and methods is that once a drawing or design is created on a Computer Aided Design (CAD) system, there may be defects in the design that are difficult to locate or find. For example, based on the resolution of a monitor and the complexity of the design, it may be difficult to find gaps or overlaps where two lines seem to connect, but in actuality, do not. These gaps an overlaps become a problem when trying to make a proper toolpath because a CAM program requires a clean, closed shape when making a toolpath. It would be advantageous for a system to include functionality that can automatically (or semi-automatically) detect and fix these gaps and/or overlaps in a drawing that are very difficult and tedious to find visually.
Yet another disadvantage of current plasma cutting systems and methods occurs at the junction of two lines, for example at a corner of a square. In a typical plasma cutting application, the quality of the cut is dependent on a constant feed-rate of the plasma torch as it cuts. Because the torch needs to slow down at these corners, there is a degradation of the quality of the cut along dross buildup at each corner. It would be advantageous for a system to include functionality that can automatically (or semi-automatically) determine where these corners will occur and using the system information, including feed-rate and machine acceleration limits, determine the optimal path to minimize inferior plasma cuts. The same methodology can be used to improve the quality of corners in other cutting methods such as laser, waterj et and oxy-fuel cutting.
Another disadvantage of current sheet metal cutting systems, multi axis CNC technologies, robotic technologies and methods is the dangerous use of wireless phone applications to control a plasma cutter, milling machine or other cutting machine. If the user inadvertently leaves the room where the machining equipment resides, the equipment may continue to operate creating a dangerous situation. It would be advantageous for a system to include functionality that can automatically shut down equipment or pass control to another user when the user (using a mobile application) leaves the vicinity or the room.
Accordingly, there is a need for an improved system, device, and method for providing improved functionality for CAD/CAM/CNC systems.